Vector 4 - Page 187

VECTOR GRAPHIC, INC.
SYMPTOM
CHECK
NORMAL
ABNORMAL
4, No parallel and/
or Centronics-type
peripherals functioning
a) WR U95-36
Active low
a) Check U83-3; if
normal, replace U83
b) RD U95-5 Active low
b) 2?Check U84-11,
U84-12 for active low
wave, If abnormal (?),
replace Z80. (?)
Check U84-13 for low
(@). If normal, (?)
replace Ull4.
c) Af U95-9
d) A1 U95-8
¢ & d) Check ad-
dress lines A
and Al on Z80.
normal, replace Uus.
e) CS U95-6
Active low (<3vde)
e) Check UT74-9 and
U74-10 for active high
pattern. If normal(?),
replace U74., If
abnormal, replace U35,
It is assumed here that the data bus is functioning properly.
NOTE
properly, isolate to the buffer, transceiver, or processor.
vV 3-4
7200-0001
If the data bus is not functioning
09-01-82